PC Bus on the Factory Floor

From a technical standpoint, the PC card form factor does not lend itself well to industrial applications. Standard pin-and-socket (DIN) connectors have proven themselves much more reliable than the card-edge connector. Also, the bus connection is physically located next to the I/O connector on the back of the card, with the bulk of the full-sized card away from both. This makes it difficult to isolate the sensitive computer bus from the harsh plant environment. The mechanical mounting of the cards in the computer is adequate for the office or home but not for the rugged factory environment. Temperature is another factory floor problem that will wreak havoc with standard office PCs, and fans and filters may not provide an acceptable resolution of the problem. 

Why the PC Bus? 

Other microcomputer bus architectures in use on the plant floor are the VMEbus, Q-bus, STD Bus, and Multibus. Some of these products offer certain advantages over the PC Bus, such as board size, bus speed, and connector type. However, the marketplace offers the development engineer a broad range of I/O and other functional control cards for PC Bus-based equipment which he can use for his particular application. The 8088/80286 family of processors may not be ideal from an architectural or programming standpoint, but there is an enormous amount of useful and varied applications and development software for these processors and the PC Bus. The PC Bus offers a high level of standardization, support, and performance in a competitive microcomputer marketplace.

Graphics Displays 

Nematron Corp.'s IWS-4000 Series Ultra Workstation is a NEMA 4/12-sealed unit with built-in, 14-in., EGA/CGA-compatible color monitor and 51-position, sealed membrane keyboard. Fully AT-compatible, the Ultra Workstation is driven by an 80286 microprocessor, featuring three expansion slots for AT/XT compatible hardware cards. The monitor provides 640 x 350 addressable points for pixel-based color graphics. The system memory includes 1 Mbyte of RAM and a choice of 20 Mbytes hardened disk drive or a solid-state, disk module with two drives, each containing 720 Kbytes of battery-backed CMOS memory. 

The Workstation features ports for RS-232/422 communications, parallel printer, floppy disk, and SCSI. The Vectra Industrial PC system from Hewlett-Packard consists of a ruggedized AT-compatible PC, a display unit, and a keyboard rack. The Vectra system is based on an 8 MHz clock and features 630 Kbytes main memory, 1.2 Mbytes flexible disk drive, and optional 20 Mbytes hard disk. The graphics display unit is a 13-in., high-resolution color monitor and supports CGA or EGA modes. Packaged for factory use, the Vectra will operate in temperatures to 60 C, in humidity to 95 percent noncondensing, and under continuous vibration. 

Stand-alone Control 

The 4000AT system from ADAC Corp. offers stand-alone data acquisition. An XT/AT-compatible backplane provides slots for four full-size cards and four half-size cards. The passive backplane allows a choice of 80C88 (640 bytes memory) or 80286 (1 Mbyte memory) microprocessors. A variety of I/O signal conditioning modules is available including analog input, analog output, and digital input/output. 

The plug-in design of the 4000 series modules facilitates replacement or servicing without disturbing system wiring. The three-piece, stand-alone design of Comark Corp.'s XT/AT-compatible EXPERT system consists of the computer, display, and keyboard unit. The AT unit features a 10-slot, passive backplane (8 AT and 2 PC slots), an 80286 processor card (6/8/10 MHz operation), and the Phoenix AT BIOS. The XT system uses an 8088 motherboard (8 slots) and has 640 Kbytes on-board RAM. The EXPERT system is housed in a corrosion-resistant, stainless steel enclosure with all components attached to a removable tray for easy servicing. The NEMA 4/4X keyboard is a sealed-membrane, 84-key model with 10 programmable function keys and an 18-key numeric pad. CGA or EGA display units are available.

Jawest Technology now offers its own version of the industrial embedded PC. The motherboard adopts a unique design,(watchdog), remote wakening, automatic reset, Working temperature: - 20 ~ 65°C, and Expandeddisplay for Multi-tasks.